In any drydock I've ever been in, the clearance below the bottom of the hull would be far too short to drop much of anything out. Those original boilers are tall -- they reach from the bottom of the (old) hull to several feet above the main deck. Hull depth is at least 14 feet, so the boat would have to be sitting AT LEAST 15 feet above the floor of the drydock to drop them out that way. I'm thinking more along the lines of cutting them up, taking out piece by piece (big pieces). But I'm not a shipyard superintendent, either, and those guys are pretty good at coming up with ideas.